On top of that, Twitter CEO Dick Costolo revealed that the social network is now serving 250 million tweets per day, an impressive statistic. The company has seen major growth in active users, with 30 percent of its 100 million users logging in every day in January. Today now more than 50 percent log in each day.

Twitter’s iOS 5 integration likely is not only improving signups but it’s almost certainly getting users to tweet more. Twitter integration (as seen above) allows users to tweet from many of the iPhone’s native applications, and tweets show up in the new notifications panel that can be accessed by swiping down from the top of the screen. iOS 5 has been downloaded and installed by an astounding number of Apple owners already, and it’s pre-installed on the record-selling iPhone 4S.

Costolo also apparently has an ambitious scope for how many devices he thinks Twitter can access in the coming years, reportedly saying, “We think that we can be on 2 billion devices around the world, and reach every person on the planet, and the way to do that is through simplifying.”